In the electrical trade, junction boxes—small boxes/compartments made of plastic or other materials, with at least one open wall and having entries/apertures defined in other walls—are often installed in buildings at points where electrical wires and/or other cables are to be connected to components such as sockets, switches, outlets, and/or other wires. A junction box is installed at the point where the connection is desired, usually within the building wall or ceiling, by nailing or screwing the junction box to a stud within the wall or ceiling. Cable is then brought to the junction box and extended through a passage in a junction box wall to enter the junction box interior.
In some cases, it is useful to protect the cable within the wall or ceiling, at least where it enters the junction box. For example, cables are often run through pipes or similar conduits between junction boxes so that the pipes/conduits protect the cables from moisture, vermin, or other conditions that might damage the cables or otherwise interfere with transmissions along the cables. As another example, even where pipes/conduits are not used to protect cables between junction boxes, it can be useful to install bushings within the passages in the junction box walls. These bushings present smooth entry/exit points for cables extending through the box wall passages, thereby allowing cable to be more easily run through the passages without catching on the portions of the junction box bounding the passages. These bushings also present attachment points for pipes/conduits, so that pipes/conduits for carrying cables from junction boxes may be readily affixed to the bushings (and thus to the junction boxes).
However, prior bushings manufactured for the aforementioned purposes tend to suffer from a number of disadvantages. Many provide poor protection for the cable at the junction box (e.g., providing a connection at the junction box which is susceptible to moisture, and/or which presents sharp corners/edges within the bushing). Also, many are made of multiple parts which are time-consuming to assemble, and/or which can be difficult to install, particularly when it is considered that bushings must often be installed “blind” (i.e., by touch, without being able to easily see the bushing as it is being installed).